This application relates to stands for supporting display signs, such as those for advertising or for display purposes generally, but particularly with regard to highway safety informational signs. Highway safety signs, of applicants' type, are designed to support an information display and be resiliently yielding to windy conditions which are often encountered along highways and in construction areas.
Applicant is aware of the following U.S. Pat. Nos. the disclosures of which are incorporated by reference herein:
______________________________________ 626,256; 1,013,410; 1,089,143; 1,135,372; 1,367,830; 1,449,063; 1,487,635; 1,532,865; 1,599,066; 1,662,298; 1,726,817; 1,750,118; 1,760,270; 1,828,892; 1,856,349; 1,903,683; 2,096,275; 2,099,558; 2,117,148; 2,144,038; 2,155,992; 2,164,680; 2,165,704; 2,168,912; 2,193,747; 2,243,912; 2,292,785; 2,308,525; 2,532,996; 2,602,684; 2,949,324; 3,013,381; 3,115,325; 3,616,557; 3,646,696; 3,662,482; 4,137,662; 4,498,657; 4,676,015. ______________________________________
Resilient sign stands of the type known as wind resistant sign stands are well known in the art and find use in outdoor advertising and displays, but have particular use in the highway safety field. These sign stands are portable and are designed to convey information, e.g., to motorist and the like to warn of construction along highways and other temporary hazards. In order to provide as much information and to warn as early as possible, these signs typically are quite large and provide a large surface area in which information can be displayed and conveyed to a motorist.
As a consequence of the large surface area of the signs, the signs are often subjected to a very high wind load. If the signs were rigid the wind load would be sufficient to topple or displace the sign away from its position and render the sign ineffective at warning approaching motorists; it being understood that the signs are not permanently anchored. To prevent displacement by a high wind load, the art has devised what is known as the wind resistant sign.
In general, two approaches have been taken to permit a sign to deflect resiliently upon application of a wind load. Both approaches utilize a yielding structure with a means for applying a restorative force when the sign is deflected away from its normal position, which is usually vertical. Typically the means to restore the sign to a vertical position is a spring. In the first design, the spring is attached to the sign or the sign mast and is subjected to bending about its major axis when the sign is displaced from its normal vertical position. This type of structure is disclosed in U.S. Pat. Nos. 3,662,482, 3,646,696 and 4,498,657. In the second design a spring is compressed when the sign is displaced, increasing the compressive force in the spring to provide a restorative force to return the sign to its vertical position once the wind load has been removed from the sign. This structure is disclosed in U.S. Pat. No. 4,676,015.
In spite of the numerous designs available in the prior art, a number of difficulties have remained and have not been solved by the designs presently available. Many of the prior devices do not hold the sign stand firmly and rigidly when a small force is applied to the sign. Some designs tend to flutter in the wind under gusting when rapid directional changes occur in the wind.
Many devices require the design and use of special springs for each size and configuration of sign or the use of other special or expensive parts. Some designs require too many separate parts and/or may be complex to assemble, thus requiring excessive labor costs. Some designs are also heavy, incurring greater cost in shipping. As the result of the many different design induced costs, the overall cost of many signs is such that the signs have not fully met the needs of the industry for an economical sign stand. It is these problems and others inherent in previous designs that applicants' improved design solves.
The present invention provides a sign stand for supporting signs in windy environments. The sign stand has a base with legs to support the sign and an upstanding mast which is adapted to receive and support a display sign. Applicant's resilient mechanism can readily be incorporated in the base portion of the sign itself, thus eliminating a significant number of parts and weight from the design. As an alternative, applicant's resilient mechanism can be incorporated as part of a mast received in the base. In this configuration the resilient portion can be placed more closely to the sign itself, if that is desired. In either configuration applicant's device provides vertical rigidity, that is, applicant's mechanism firmly holds a sign in a vertical position so that it may be read by an approaching motorist, for example, but also provides means which are resiliently yieldable under the influence of wind load on the sign to allow the sign to pivot and spill the wind load without toppling the sign base from its original position. Upon the removal of the wind load the sign is resiliently returned to its normal vertical position.
Applicant's device may incorporate guides which restrict flutter or the twisting movement of the sign, for example, in response to gusting wind loads and changes of wind direction. Applicant's construction incorporates a minimum of parts and can be constructed to utilize a variety of resilient spring means including elastomeric spring means either in the biscuit or solid form or in the strap or cord form, such as the well known "bungee" cord. In addition, the standard metallic coil spring may be used. None of these springs are highly specialized. Applicant's device utilizes the tension produced by elongation of the spring means to restore the sign and mechanism to a vertical position on release or removal of a wind load. Applicants' device can be readily constructed out of stock shapes and materials with a minimum of machining and construction and a minimum of specialized parts.
It is thus an object of applicant's invention to provide a resilient sign mechanism which can be produced and shipped at minimal cost.
It is thus an object of applicant's invention to provide a reliable sign mechanism which can be constructed from stock elements to provide a durable resilient sign mechanism.
It is an object of applicant's invention to provide a wind resistant mechanism which is resistant to flutter.
It is thus an object of applicant's invention to provide a wind resistant sign mechanism which operates by utilizing tension in a spring to provide a restoring force to the mechanism and return a displaced sign to a vertical position.
It is an object of applicant's invention to provide a wind resistant sign which can utilize springs of a variety of types, to provide a sign restoring force.
These and other objects of the invention will be more readily apparent by referring to the following description of the drawings and description of the preferred embodiments.